Lambda 1 at Idle

Hello,

Interested in your thoughts on this...

I can easily get my engine (3SGTE with mods) to idle at lambda 1 or thereabouts, however if "sounds" happier if I richen it up... the revs come up and it behaves better to small throttle inputs... so I tend to run it between .90 / .95.

Any thoughts on this? Is there something else I should look at?

Something else to be aware: I have no idle control on this engine, so it's controlled with the ignition advance... reason for mentioning is there is nothing else trying to hold the revs in place.

Thanks for any thoughts.

High performance engines often want to be a bit rich at idle. Just be sure that you aren't fouling plugs. Nothing wrong with idling at .90 if that's what the engine wants.

Thanks David!

David is absolutely right - camshafts with long duration and big overlap can cause loss of torque at idle due to bad VE whilst air fuel mixture slightly richer than lambda 1 can resore some torque...